Safety flap arrangement for discharge apertures in rotary lawnmower baseplates

ABSTRACT

A pivoted flap arrangement for covering the grass discharge opening in a rotary lawnmower, and comprising a cover plate, a pivoted handle on the baseplate for opening the plate, a flexed spring leaf interconnecting the plate and the handle, and an overcenter (or toggle) action between the spring and the handle whereby resilient opening force is applied to the plate when the handle is operated and when the plate has pivoted to a fully open position the handle and plate are automatically returned.

United States Patent Meyer et al.

[ 51 Jan.25,1972

SAFETY FLAP ARRANGEMENT FOR DISCHARGE APERTURES IN ROTARY LAWNMOWERBASEPLATES Inventors: Dolph Allan Meyer; Ross Leslie Phelps; David PaulSeidel; Edward l-lenry Sykes; lan Sweet Clipsham; Donald Gray; TheodoreDemetrius Ractivand, all of Milperra, New South Wales, Australia VictaLimited, Milperra, New South Wales, Australia Filed: Sept. 9, 1970 Appl.No.: 70,779

Assignee:

Foreign Application Priority Data Apr. 8, 1970 Australia ..PA0845/70 US.Cl ..56/320.2, 56/ 1 94 Int. Cl. ..A01d 55/18 Field of Search..56/320.2, 194, 202, 203, 13.3,

[56] References Cited UNlTED STATES PATENTS 3,065,588 11/1962 Shaw..56/l3.4 3,186,] 52 6/1965 Epstein 3,420,041 1/1969 lrgens ..56/320.2

FOREIGN PATENTS OR APPLICATIONS 402,989 4/1967 Australia ..56/194Primary ExaminerRussell R. Kinsey Attorney-Waters, Roditi, Schwartz &Nissen [5 7] ABSTRACT A pivoted flap arrangement for covering the grassdischarge opening in a rotary lawnmower, and comprising a cover plate, apivoted handle on the baseplate for opening the plate, a flexed springleaf interconnecting the plate and the handle, and an overcentcr (ortoggle) action between the spring and the handle whereby resilientopening force is applied to the plate when the handle is operated andwhen the plate has pivoted to a fully open position the handle and plateare automatically returned.

10 Claims, 3 Drawing Figures slsasleas Pmmw ms m2 SHEET 1 OF 2 FIGJPATENTED JANZS 1972 SHEET 2 BF 2 FIGZ SAFETY FLAP ARRANGEMENT FORDISCHARGE APERTURES IN ROTARY LAWNMOWER BASEPLATES This inventionrelates to safety flaps for rotary lawnmower baseplates and moreparticularly to those which cover the discharge aperture thereofwhenever a grasscatching receptacle on the baseplate is removed.

It is the main object of the invention to provide a cover flaparrangement for such apertures which will to a high degree safeguard anoperator or bystander against injury.

The invention, therefore, in one general form is a safety flaparrangement for covering a grass discharge aperture in a rotarylawnmower baseplate, said arrangement comprising a plate member hingedto the baseplate for gravitational closure, a pivoted control lever formanual operation to raise the plate, and resilient means connectedbetween the lever and the plate so as to be flexed by operation of thelever to draw the plate member to a fully open condition and then toeffect automatic return of the lever for release of the plate member.

A preferred form of the invention is illustrated in the accompanyingdrawings, in which:

FIG. 1 is a fragmentary perspective view of the rear end of a rotarylawnmower showing a back safety flap thereon in a closed position FIG. 2is a perspective view of the opposite side of the lawnmower to thatshown in FIG. 1, showing a grasscatcher attached and the backflap in anopen or raised position;

FIG. 3 is a side elevation showing the grasscatcher removed from thelawnmower and the backflap in the act of flying upwardly before itcommences to drop and carry the actuating lever over with it.

With reference to the drawings, the backflap 4 is adapted to close arectangular grass cuttings discharge port 5 in the baseplate of arotary-type lawnmower which normally carries a grasscatcher 6 attachedto the discharge port 5. The flap 4 is a relatively heavy metal platehingedly secured to a transverse rod 7 mounted near the top 8 of theport 5. The flap is provided with stiffening deformations 9 and integralside flaps 10.

An actuating lever 11 is pivotally secured at 12 between trunnionsformed integrally with the top 8 of the housing which defines thedischarge port 5. An arcuately curved spring strip 13 is pivotallymounted at one end to a pin 14 medially positioned in wings of the lever11. The spring strip 13 is formed from a bowed leaf of spring steelpartly straightened in assembly so that its two ends tend to drawtogether.

The lever 11 is provided with a stop 21 outwardly of the pin 14 toengage the spring strip 13 and limit its pivoting movement. Spacingbetween stop 21 and spring 13 is such as to impose an additional forceon the spring 13 at and near the closed position of the flap 4 to assistin forcibly holding the flap closed. In effect the action of the stop 21is to reverse the direction of the line of force normally applied by thespring 13 when the flap approaches its closed position so as to providethe main shutting force for the flap 4. A torsion spring 7A is providedon rod 7 to permit an even larger shutting force in the flap 4. Theother free end of the strip 13 is anchored at 15 in an aperture 16 inthe flap 4. When the catcher 6 is removed from the mower the flap willbe in the lowered and closed position, as shown in FIG. 1. The catcher 6can be secured to the mower by engaging pins 17 on said catcher withhooks 18 on the mower handle 19. The actuating lever 11 can be swungover towards the front of the mower, as shown in FIG. 2, so that theflap 4 is pulled upwardly by tension in the spring strip 13. The flap 4will now close an aperture 20 on the top of the catcher 6 and open thedischarge port 5 at the rear of the mower. Grass cuttings will now befed into the catcher 6 as mowing operations are carried out. Projectingtongues 22 on the grasscatcher 6 and 23 on the flap 4, or other suitablemeans, may be employed for interlocking purposes requiring depression ofthe flap 4 for release of the grasscatcher 6, while serving otherwise tohold the grasscatcher 6 on the lawnmower.

Opening of the flap may frequently be impeded, due to sticking, cloggingor the like, and to ensure efficient operation under all conditions anauxiliary leverage device is incorporated. This consists of a fixedpeaked projection 24 on the baseplate between the trunnions and beneaththe lever 11 in the latters normal position. The spring strip 13 has anextend ing end portion folded back upon itself around the pin 14 to forman auxiliary leaf spring 25 with an inturned tongue 26 at its endadapted to bear upon the underside of the spring strip 13. Withoperating movement of the actuating lever 11, therefore, the auxiliaryspring 25 will be carried over to contact and rub upon the projection24. With continued operating movement of lever 11 leverage will beexerted upon the flap 4, via contact of the tongue 26 with spring strip13, about the fulcrum of the fixed projection 24. After the flap 4 hasopened and is pivotting freely further operating movement of lever 11may cause the end of the auxiliary spring 25 to pass over and beyond thepeak of the projection 24. In the fully operated condition of lever 11it abuts a stop pad 27 on the top of the baseplate for precisepositioning. In this position and with the grasscatcher attached to thelawnmower the flap 4 will be locked to the grasscatcher by tongues 22and 23 with the spring strip 13 spaced above the peak of the fixedprojection 24. The flap 4 if depressed for unlocking of the grasscatchermay flex the spring strip 13 over the projection 24 but due to anovercenter alignment of the pin 14, projection peak and anchoring point15, the lever 11 is not pulled back.

Hence as soon as the catcher 6 is full, it may be removed withoutstopping the mower. When the catcher 6 is clear, as shown in FIG. 3, thetension in the spring strip 13 will first draw the flap 4 up to a higherelevation than it occupied when the catcher 6 was in place. In thisposition then the anchor point 15 of the spring strip 13 passes to theupper side of the alignment of the projections peak and pin 14 andserves to unlock the lever 11 for return to normal. The weight of theflap 4 assisted by tension in the torsion spring 7A will now pull thelever 11 over towards the rear of the mower and the flap will bereleased and be returned to the closed position as shown in FIG. 1.Residual tension in the spring strip 13 abutted against stop 21 on thelever applies a force acting between anchorage l5 and pivot 12. Thisforce, augmented to a degree by the force supplied by the torsion spring7A in this position will keep the flap 4 shut against the action of theair blast from the mower blades and also against the impact with saidflap of any objects thrown off by the rotating blades.

The flap-actuating lever 11 is located high on the top of the mower reardischarge port 5 so that an operator does not have to stoop down to movesaid lever. The spring 13 and lever arrangement is compact, simple andinexpensive to manufacture. It is especially resistant to sticking fromaccumulation of dust and grit. The force required to move the lever 11is small due to the relatively great distance through which said leveris capable of moving.

It will be seen that a great measure of safety is provided by the coverflap arrangement of the invention. At all times when the grasscatcher 6is not attached the discharge port 5 is closed by the flap 4.Furthermore, the catcher 6 may be placed in position on the lawnmowerbefore the flap 4 is opened, and opening is effected without theoperator having to reach inside the catcher. Also, the feature ofautomatic closure of the flap 4 ensures that the flap is permitted tostart its closing sequence only after the last portion of thegrasscatcher has released it, thus avoiding grass accumulated near theentry to the catcher being swept away by the flap as it closes.

What we claim is:

l. A safety flap arrangement for covering a grass discharge aperture ina rotary lawnmower baseplate, said arrangement comprising a plate memberhinged to the baseplate for movement between open and closed conditions,a pivoted control lever for manual operation to move the plate from itsclosed condition, and resilient means connected between the lever andthe plate so as to be flexed by operation of the lever to draw the platemember to its open condition and to effect automatic return of the leverto restore the plate member to its closed condition.

2. A safety flap arrangement according to claim 1, wherein the lever ispivoted by one end to the baseplate above the discharge aperture andclosing of the plate is effected at least partly by gravitational force.

3. A safety flap arrangement according to claim 2, wherein the resilientmeans is elongated and pivotally fixed by one end to an intermediateposition on the lever.

4. A safety flap arrangement according to claim 3, wherein the platemember is constructed to engage with a grasscatcher fitted to thelawnmower to be arrested in its opening movement short of a fully openedcondition, and wherein in said arrested position the relationship of thelever pivot and the resilient means pivot on the lever to the anchoringpoint of the resilient means on the plate member is such as to create anovercenter action locking the lever in an operated position.

5. A safety flap arrangement according to claim 4, wherein in said fullyopen condition of the plate member the anchoring point of the resilientmeans passes beyond an alignment with the lever pivot and the resilientmeans pivot on the lever to unlock said lever and allow its automaticreturn.

6. A safety flap arrangement according to claim 1, wherein the resilientmeans is a spring strip the tension in which tends to bow it to reducethe spacing between its ends.

7, A safety flap arrangement for a grass discharge orifice on abaseplate of a rotary lawnmower, said arrangement comprising a coverplate pivotally movable between fully open and closed conditions, amanually operable control lever pivoted to the baseplate, resilientmeans between the plate and the baseplate urging the cover plate to'theclosed condition, a bowed spring leaf whose ends are forced apart forconnection between the lever and the cover plate, and an overcenterdisposition of the connecting points of the lever to the baseplate andthe bowed spring to both the cover plate and the lever whereby the leveris locked in its operated position until the cover plate nears its fullyopen condition to draw the lever from its operated position thusremoving an opening force on the cover plate.

8. A safety flap arrangement according to claim 8, wherein an auxiliaryspring is carried by the lever and a projection is fixed upon thebaseplate for engagement by the auxiliary spring during operation of thelever to cause the auxiliary spring to contact said bowed spring and toprize the cover plate from its closed condition if it should bind.

9. A safety flap arrangement according to claim 8, wherein the auxiliaryspring is an end portion of said resilient means folded back upon itselfand provided with an inturned engagement tongue.

10. A safety flap arrangement according to claim 7, wherein an abutmentis provided upon the lever to engage the bowed spring when the lever isunoperated to exert a force upon the cover plate tending to hold itclosed.

1. A safety flap arrangement for covering a grass discharge aperture ina rotary lawnmower baseplate, said arrangement comprising a plate memberhinged to the baseplate for movement between open and closed conditions,a pivoted control lever for manual operation to move the plate from itsclosed condition, and resilient means connected between the lever andthe plate so as to be flexed by operation of the lever to draw the platemember to its open condition and to effect automatic return of the leverto restore the plate member to its closed condition.
 2. A safety flaparrangement according to claim 1, wherein the lever is pivoted by oneend to the baseplate above the discharge aperture and closing of theplate is effected at least partly by gravitational force.
 3. A safetyflap arrangement according to claim 2, wherein the resilient means iselongated and pivotally fixed by one end to an intermediate position onthe lever.
 4. A safety flap arrangement according to claim 3, whereinthe plate member is constructed to engage with a grasscatcher fitted tothe lawnmower to be arrested in its opening movement short of a fullyopened condition, and wherein in said arrested position the relationshipof the lever pivot and the resilient means pivot on the lever to theanchoring point of the resilient means on the plate member is such as tocreate an overcenter action locking the lever in an operated position.5. A safety flap arrangement according to claim 4, wherein in said fullyopen condition of the plate member the anchoring point of the resilientmeans passes beyond an alignment with the lever pivot and the resilientmeans pivot on the lever to unlock said lever and allow its automaticreturn.
 6. A safety flap arrangement according to claim 1, wherein theresilient means is a spring strip the tension in which tends to bow itto reduce the spacing between its ends.
 7. A safety flap arrangement fora grass discharge orifice on a baseplate of a rotary lawnmower, saidarrangement comprising a cover plate pivotally movable between fullyopen and closed conditions, a manually operable control lever pivoted tothe baseplate, resilient means between the plate and the baseplateurging the cover plate to the closed condition, a bowed spring leafwhose ends are forced apart for connection between the lever and thecover plate, and an overcenter disposition of the connecting points ofthe lever to the baseplate and the bowed spring to both the cover plateand the lever whereby the lever is locked in its operated position untilthe cover plate nears its fully open condition to draw the lever fromits operated position thus removing an opening force on the cover plate.8. A safety flap arrangement according to claim 8, wherein an auxiliaryspring is carried by the lever and a projection is fixed upon thebaseplate for engagement by the auxiliary spring during operation of thelever to cause the auxiliary spring to contact said bowed spring and toprize the cover plate from its closed condition if it should bind.
 9. Asafety flap arrangement according to claim 8, wherein the auxiliaryspring is an end portion of said resilient means folded back upon itselfand provided with an inturned engagement tongue.
 10. A safety flaparrangement according to claim 7, wherein an abutment is provided uponthe lever to engage the bowed spring when the lever is unoperated toexert a force upon the cover plate tending to hold it closed.